Aitor Karanka at a Real Madrid press conference in April 2013. He has agreed a deal with Middlesbrough to 2016. Photograph: Angel Martínez/Real Madrid via Getty

Aitor Karanka will be introduced as Middlesbrough's new manager on Wednesday morning after finally rebuffing sustained overtures from Crystal Palace.

Steve Gibson, Boro's owner, is hoping that Karanka, José Mourinho's former assistant at Real Madrid and a highly regarded coach, can replicate the success once enjoyed by Steve McClaren, who swapped life as Sir Alex Ferguson's No2 at Manchester United for the Riverside.

Since McClaren left Boro for an ill-fated stint as England coach in 2006 the club have foundered, slipping into the Championship as Gareth Southgate, Gordon Strachan and, most recently, Tony Mowbray all failed to build winning sides.

Karanka, a 40-year-old former Real central defender, has seen his path to the north-east smoothed by the influence of Jorge Mendes, his agent, and Peter Kenyon, the former Manchester United and Chelsea chief executive, both of whom advise Gibson.

Although tempted strongly by Palace, Karanka, a fluent English speaker who has watched DVDs of all Boro's games this season, was understood to be swayed partly by a recent visit to the club's international-class training facility at Rockcliffe Park, near Darlington.

Although Mowbray's successor has never been a manager in his own right, he is highly thought of in Spain and Mourinho believes Gibson has picked a winner. "I know Karanka very, very well," said Chelsea's manager. "He was my assistant for three years and I think the club that gets him will be very lucky."

Karanka, who is expected to bring in his own backroom staff, has agreed a two-and-half-year contract on Teesside, with his immediate priority being to try to narrow the eight-point gap separating Boro from the Championship play-off places. His first match will be at Leeds United on Saturday week.